A broad coalition of environmental and other groups urged Gov. Martin O'Malley Tuesday to oppose development of a natural gas export terminal on the Chesapeake Bay, calling it an unacceptable environmental and safety threat.

Members of the coalition, which includes more than 120 local, statewide and national groups, gathered outside the Maryland Public Service Commission offices just before noon to outline their concerns over the proposed liquefied natural gas (LNG) export facility at Cove Point in Calvert County. They contended it would pollute the air and bay, undermine state efforts to combat climate change and expose nearby residents to the risks of a catastrophic explosion, either by accident or from a terrorist attack.

If approved, the $3.8 billion gas liquefaction complex proposed by Dominion, a Virginia-based energy company, would be the first on the East Coast to export LNG anywhere in the world. Three others have received at least preliminary federal approval on the Gulf Coast.

Mike Tidwell, head of Chesapeake Climate Action Network, contended in an interview that the project would undermine the O'Malley administration's efforts to curb climate-warming greenhouse gas emissions in the state.

Based on estimates provided by Dominion, he said, the export complex - which would include a gas liquefaction plant and a 130-megawatt gas-burning power plant - would release 3.3 million tons/pounds of carbon dioxide annually. That would make it the fourth largest single source of climate-altering carbon in the state, Tidwell said, more than most of the coal-burning power plants in Maryland.

Tidwell also predicted that opening an export terminal on the bay would accelerate natural gas drilling using hydraulic fracturing in Pennsylvania, Ohio and possibly even western Maryland.

Others at the demonstration Tuesday voiced concerns over pollution from up to 90 LNG tankers expected to visit the terminal a year, as well as over disruption from construction of the terminal and related infrastructure elsewhere. Some said they worried about risks of an accidental explosion or terrorist attack, noting that the terminal is close to a residential community and three miles from the Calvert Cliffs nuclear power plant.

Dominion spokesman Daniel Donovan said the Cove Point complex would be "the most environmentally compatible facility of its kind."

"The people of Maryland stand to receive significant benefits from this project," Donovan added in an email. He said the terminal construction would yield "thousands of jobs and many millions in new government revenues – while the nation can help meet the energy needs of two important allies." The LNG would be exported to Japan and India.

The O'Malley administration has yet to take a position on the project. Abigail Hopper, the governor's energy adviser, said he was "reviewing the issue very carefully.

"As you know," she added in an email, "reducing greenhouse gas emissions in Maryland is an important priority for the governor, and he remains committed to ensuring that happens."